A Bright Green 'Christmas Comet' Will Fly the Closest To Earth In Centuries

On Sunday night, a comet that orbits between Jupiter and the sun will make its closest approach to Earth in centuries. According to Tony Farnham, a research scientist in the astronomy department at the University of Maryland, the comet will appear as a bright, fuzzy ball with a greenish-gray tint. "You've got a one-kilometer solid nuclear in the middle, and gas is going out hundreds of thousands of miles," says Tony. The comet glows green because the gases emit light in green wavelengths. The New York Times reports: The ball of gas and dust, sometimes referred to as the "Christmas comet," was named 46P/Wirtanen, after the astronomer Carl Wirtanen, who discovered it in 1948. It orbits the sun once every 5.4 years, passing by Earth approximately every 11 years, but its distance varies and it is rarely this close. As the comet passes by, it will be 30 times farther from Earth than the moon, NASA said. The proximity of 46P/Wirtanen provides an opportunity to research the tail of the comet and see farther into the nucleus.

The comet is visible now but it will shine even brighter on Sunday as it reaches its closest approach, 7.1 million miles from Earth. That may sound really far, but it is among the 10 closest approaches by a comet in 70 years, NASA said. Only a few of those could be seen with the naked eye. Don't worry if you miss the comet on Sunday. It should be just as visible for a week or two because its appearance will change gradually. After it moves on, it won't be this close to Earth again for hundreds, if not thousands, of years. Online charts can help pinpoint its location.

Comments

So went outside and I looked up tonight...

[93 Escort Wagon]

But all I got was a face full of rain. I live in the Pacific Northwest, you insensitive clod!

If only this could have been posted pre Monday

[Crashmarik]

Maybe on say Friday ?

Oh well people will still get to see the comet.

That's a terrible chart

[Solandri]

Doesn't name the constellations. In fact it's difficult to even see the constellations on it. Try this chart from Sky and Telescope. The comet is currently between Taurus and the Pleiades. Most occasional stargazers can locate those.

Don't expect much though. It's currently at its peak magnitude of 3.9. Magnitude 6.0 is the dimmest you can see in dark skies, with most visible stars falling between -1.5 and +5. You're not going to see it with the naked eye from a city. Maybe a fuzzy blob with decent binoculars. The closest bright star is Aldebaran, which at magnitude 1 is about 15x brighter.

Moving FAST!

[kbahey]

This comet is moving really fast!

Last night was the first break in the clouds in about a month and a half. So I got out my astrophotography rig, which is based on the open source OnStep STM32 telescope controller.

The moon was bright, and there was too much moisture in the atmosphere. So, not ideal conditions.

As far as comets go, this one is underwhelming. It lacks a tail, and is below naked eye visibility. But what is remarkable, is that this comet was sure moving fast against the background stars.

A 5 minute exposure shows a fuzzy streak that goes in a different direction than the streaks from stars due to a hasty and inaccurate polar alignment.

Here is a screenshot of the 5 minute exposure, and another 60 seconds exposure.

Clouds rolled over and I had to call it a night.

Oh, and if you want an Open Source telescope controller, here are more videos on OnStep on the STM32.